Combined piano and electrical monophonic instrument



April 19, 1960 .1. M. HANERT 2,933,004

COMBINED PIANO AND ELECTRICAL MONOPHONIC INSTRUMENT Filed Aug. 29, 1952 2 Sheets-Sheet l April 19, 1960 J. M. HANERT 2,933,004 COMBINED PIANO AND ELECTRICAL MONOPHONIC INSTRUMENT Filed Aug. 29, 1952 2 Sheets-Sheet 2 HIGH-LOW MELODY seuzcroz 34. H5 -55 IEANEE SELEC-TQQ IRANQE SELECTOR. r118 FREQ- FREQ FREQ- DVIDER DVDE DlVfDEz 1 98 99 (00 VlEaiZATO 3' SWITCHING a APPARATUS l I 1 I f 1 l I L.'""

TONE AMPLIFIER CONTROLS & VOLUME I50 +150 QCONTROL.

2- :54 5+ OFF LOUD United States Patent COMBINED PIANO AND ELECTRICAL MONOPHONIC INSTRUMENT John M. Hanert, Des Plaines, 111., assignor to Hammond Organ Company, a corporation of Delaware Application August 29, 1952, Serial No. 307,034 '5 Claims. (Cl. 84--1.01)

. ing percussive tones of the piano with means for producing sustained tones such as those of the pipe organ. An example of this consists of a pipe organ in which one of the stops causes actuation of a piano action under the control of the pipe organ keys. 'When the pipe organ stops as well as the piano stop are drawn for a single manual the efiect is no longer that of solo and accompaniment, but rather is a combination of percussive and sustained tones on all of the keys. Only when the sustained tone is registered for one organ manual and the percussive tone for another manual does the desirable duet condition of soloist and accompanist prevail.

Another form of musical instrument, which may be electronic, consists of a monophonic instrument which is played on a separate keyboard apart fromv the piano. This instrument has an unquestioned appeal tov the musician who prefers to play music of a quiet and relatively simple character in which the accompaniment may be completely controlled by the player's left hand. However, for the more advanced pianist the desirability of being able to utilize all the fingers of both hands in playing in a polyphonic style is very great. Such musicians would like to play on the piano withv countermelodies as well as leading melodies with one hand.

With the instrument of this invention the above objections to the piano-pipe organ type ofinstrument as well as to the separate melody keyboard type of instrument are completely overcome and. the, master musician finds himself in no way hampered in his ability to play interesting figures, countcrmelodies, etc., on the piano while at the same time playing a sustained melody as a solo. In general, this effect is produced by means of an electronic instrument by which a sustained tone may be produced, the pitch of which mayv selectively correspond to either the highest or lowest ofa plurality of keys which are held depressed at the same time. Electrical switches for controlling the. monophonic instrument are operated by the piano keys so that simultaneous sounding of the piano and electrical instrumentare to be had when any piano key is depressed.

It is therefore the object of the present invention to produce an improved piano having means whereby sustained tones may be produced at will, the sustained to'nes correspondingin pitch selectively to either the highest or the lowest of a plurality of depressed keys.

A further object is to provide an improved piano in ice which the melody tone may be sustained and have its intensity controlled independently of the loudness of the piano tones.

A further object is to provide an improved electrical musical instrument of the monophonic type, in which key controlled switching circuits are selectively adjustable so that the highest or lowest of several keys or any of a number of groups of keys, which are depressed at the same time, shalt determine the pitch of the tone produced.

A further object is to provide an improved piano having means for producing sustained tones for the rendition of the melodic or solo portion of a selection and independently of the operation or" the sustained and sustenuto pedals of the piano.

Other objects will appear from tion, reference being in which:

Fig. 1 is a perspective view invention.

Fig. 2 is in part a section and in part an elevational view of a piano key action and switching mechanism; and

Fig. 3 is a schematic wiring diagram of the electrical portion of the improved piano.

The piano comprises a case 10 which may be of any suitable design and incorporates the usual 88 note keyboard 12, soft pedal 14, sustenuto pedal 15, and sustaining pedal 16. In addition to the conventional parts of the case, there is provided a knee-operated swell or expression lever 38, by which the intensity of the solo or melody tones may be controlled. Mounted on the vertical board behind the keyboard are a plurality of stop-tablets, 20 to 36, inclusive, for controlling the quality and other attributes of the solo or melody tones.

The keyboard 12 comprises a plurality of keys 40, pivoted on a balance rail 42, and guided by a pivot pin 44 and a forward end guide pin 46, these pins being secured in the keybed frame 48. Each of the keys is adapted to operate an action which may be of conventional construction but is herein illustrated as including a wippen 50 operating through a jack 52 to cause a hammer 54 to strike one or more piano strings 56. The wippen also operates a damper lever 58 by means of a damper spoon 60 to swing the damper head e2 away from the string 56 before the hammer strikes the string and to re-engage the string to damp its vibration upon release of the key, provided a damper lifting rod 64 has not been operated by the sustaining pedal 16. The action is provided with the usual back-stop 66 and check 68 as well as the usual limit stops and springs.

In addition to operating the action, each of the keys .0, within the range approximately from A1==l10 c.p.s. to C6=2093 c.p.s., also operates a switch actuator 70 of insulating material which extends downwardly through a suitable guide slot 72 formed in the key bed frame 48. Upon depression of the key the actuator 70 engages switch fingers 74 and 76 successively to close a switch 78, open a switch 7?, and close a switch 86. One of each of the pair of contactors for the switches 78 and 79 is carried by a switch finger 75. The switch fingers 74, 7S, and 76 are flexible and resilient so that after switch 73 is closed the switch finger is flexed downwardly to open switch 79. One contact of switch 79 is carried by a rigid arm 32 mounted together with the other switch fingers in a suitable stack of insulating blocks 84. The switch finger '76 carries one of the contacts of switch 80 while the other contact thereof is mounted on a three section bus bar 86a, 86b, and S6c. The section 86a of the bus bar preferably extends from the switch 550 for the key A1 to the switch for key E3, the section 86b extends from the switch for the key F3 to the switch for the key B3, while the section 860 extends from the switch for the key C4- to the switch for the key C6. The switch asthe following descriphad to the accompanying drawing of a piano incorporating the 3 i sembly is enclosed in a suitable housing S secured to the bottom of the key bed frame 48.

Electrical tone signals are produced by a solo oscillator 96, which provides a frequency controlling signal to three alternate pulse responsive cascaded frequency divider stages 98, 99, and 1%. Each of these divider stages successively halves the frequency so as to produce octavely related tone signals.

The solo oscillator comprises triodes 1112 and 103 having conventional components so as to produce substantially sine wave oscillations, the frequency of which is determined mainly by a resonant circuit comprising a capacitor ores and one or more of a plurality of serially connected inductances L106 which are connected in parallel with the capacitor C104 by operation of the key switches 76 and 79. The inductances D106 are connected in series and the junction between each adjacent pair is connected to the switch finger 74 of one of the switches The switches 79, it will be observed, are connected in series in such manner that when a plurality of keys are depressed at the same time either the highest or the lowest of the several keys will be effective to tune the oscillator to the pitch represented by the highest or lowest key. Whether the highest or lowest of a number of keys depressed at the same time shall determine the pitch of the oscillator is controlled by a high-low melody selector tablet 36 which, when at its rightward position as shown in Fig. 3, opens a plurality of switches 108 and moves a switch 110 to the position shown in full lines. When the selector tablet 36 is moved to the left switches 108 are closed and switch 110 moved to its dotted line position, and the switches 108 connect the switch fingers '75 to ground. Under these circumstances, closure of a switch 78 by operation of the highest of a plurality of depressed keys connects to ground the inductances L106 associated therewith, and all other similar inductances associated with higher keys, and elfectively short-circuits all of the inductances L106 associated with lower keys.

However, when the melody selector 36 is operated to open switches 108, the lowest of a plurality of depressed keys will be eifective to tune the oscillator because the switches 79 are connected in series and only the lowest of these switches is connected to ground.

Upon occasion, in playing certain musical selection it is desirable to limit the range in which either the lowest or the highest depressed key will be effective to control the sounding of a tone, and this is accomplished by means of range selector tablets 34 and 35 which respectively operate switches 114 and 115. These switches, it will be noted, are connected in series between the bus bar sections 36a and 36b, and 86b and 860, respectively. It will be noted that when the switch 110 is in its full line position, to effect playing of the lowest note, bus bar section 860 is connected to a conductor 118, whereas, when switch 110' is in its dotted line position the conductor 118 is connected to the bus bar section 860. When the conductor 118 is grounded by closure of one of the switches 80 a cut-off bias potential is removed from a pair of control pentodes 120 and 121, as will be further described hereinafter.

A vibrato switching apparatus 124, rendered operative by a control tablet 33, operates at a vibrato frequency to connect and disconnect a small tuning capacitor C126 in the resonant inductance-capacitance circuit of the oscillator, to introduce the vibrato effect whenever desired.

The output of the triode 193 is impressed upon the grid of a triode 128, the output of which is a Wave having a nearly vertical front to insure reliable operation of the first frequency divider stage 98. The dividers 98, 99, and 100, may be of any suitable construction but are preferably of the alternate pulse responsive type'which produces a rectangular form of output signal. Each stage preferably includes a pulse sharpening and rectifying triode, so as to have a signal available for reliably 'duce a smooth decay of the tone.

operating the following frequency divider stage and for producing a tone signal having a large number of even as well as odd harmonics. It is desirable to have available in the output of the intrument tones of the string type in addition to the tones of the woodwind type which may be obtained from the rectangular wave outputs of the frequency divider stages.

The outputs of the solo oscillator 96, and of the frequency dividers 98, 99, and 100, are adapted to be selectively coupled to the input of a preamplifier triode 130 by operation of tablets 25 to 32, each of which operates a switch 132. The switches 132, upon closure, conduct the signals from the oscillator and frequency divider stages through decoupling resistors R134 to a signal collecting bus bar 136, the latter being connected to the input of the preamplifier triode 130.

The output of the preamplifier 130 has a plurality of tone control circuits 138, connected between it and ground, the various meshes of these circuits being selected by operation of one or more tone control tablets 21 to 24 inclusive.

The output of the preamplifier, as modified by the tone controls, is transmitted by transformer 140 to the input circuits of the tone intensity envelope control pentodes 120 and 121.. The cathodes of these pentodes are positively biased with respect to their control grids by a voltage divider mesh comprising resistors R142 and R143, connected in series between a B-\- terminal and ground, the junction of these resistors being connected to the cathodes of the pentodes 120 and 121. When one of the playing keys is depressed to close its switches to connect conductor 118 to ground, the voltage on the cathodes of the pentodes 120 and 121, is rapidly reduced at a rate depending mainly upon the time constant of resistor R144 and capacitor C146. Upon release of the playing key the voltage on the cathodes of the pentodes 120 and 121 rises at a rate determined by the time constant of the .mesh comprising R142, R143, and C146, to pro- If a fast attack is desired tablet 201 is operated to close a switch 148, which connects the cathodes to a center tap on the secondary of the transformer 140 through a capacitor C150. The center tap on the transformer secondary is connected to ground through a grid resistor R152. The output circuits of the control pentodes 120 and 121 are suitably coupled to a power amplifier 154, which includes a volume control operable by lever 18 (Fig. 1), and the output of which is supplied to a speaker 156. The lever 18, when in its leftmost operative position opens a switch 158 in the output circuit to assure silence when the melody section of the instrument is not being used.

In playing the instrument the musician determines from the selection to be played whether he wishes the highest or lowest of several depressed keys to control the frequency of the solo oscillator, and positions the selector tablet 36 accordingly. If he wishes the melody tone to be produced only within a certain range of the gamut of the melody section of the instrument he will move the range selector tablets 34 and 35 to the preferred positions. If both switches 114 and 115 are closed and ii the switches 108 and are in the positions shown in full lines in Fig. 3, the lowest of a plurality of simultaneously depressed keys will be effective to determine the frequency of the solo oscillator, whereas, when the melody selector 36 is operated to move switches 108 and 110 to their dotted line positions, the highestof a plurality of depressed keys will determine the pitch ofthe solo oscillator. If the switch is open and switch 110 is in its full line position, then the keys C4 to C6 will be ineffective. to remove the cut-off bias of the control pen- :todes and 121, because under these circumstances, the conductor 118 will be connected only, to the bus barsections 86a and 86b by a conductor 160.

When the melody selector tablet 36 is operated to move switches 108 and 110 to their dotted line positions,

the highest key depressed will determine the pitch of the oscillator 96. If it is desired to limit the solo tones within the range C4 to C6, the switch 115 is opened by the range selector 35, thereby rendering the switches 80 associated with lower keys ineffective to remove the cutoff bias on the pentodes 120, 121. If it is desired to extend the operable range to the key F3, the range selector 35 is operated to close switch 115 and the selector 34 is operated to open switch 114. Under these circumstances, the switches 80, associated with keys below F3, will be ineffective to remove thebias on the control pentodes 12-5) and 121.

When the lowest note is to carry the melody, the switches Hi8 and the switch 110 are moved to their full line positions, whereupon the lowest of several depressed keys will determine the pitch of the solo oscillator. The range in which the lowest depressed key shall control the pitch of the oscillator is determined by the condition of switches 114 and 115. If switch 114 is closed and switch 115 is open only the keys within the range -A1 to B3 will be effective to remove the cut-off bias on the control pentodes 120, 121.

The player thus has at his control not only whether the highest or lowest of the depressed keys shall be determinative of the solo tone but also may limit the solo tone range, if desired, so as to make possible the use of other keys not carrying the solo part to provide piano accompaniment.

When the instrument is conditioned to be selective of the highest of a plurality of depressed keys the musician may play in third and sixth interval with the highest note sounding on both the piano and sustained melody instrument, whereas the lower note sounds on the piano only. Thus the highest note is of a solo character and is easily differentiated from the lower piano note in an acoustic musical tone sense. Also the musician may play full chords in which the highest note is the melody note and is heard as a sustained tone produced by the monophonic instrument as well as a percussive piano tone. Still another alternative is to play the melody in octaves in which the monophonic instrument is responsive to the highest note and the piano is responsive to both the highest and lowest note.

When the monophonic instrument is arranged to select the lowest of a plurality of depressed keys many interesting eh'ects may be had with the right hand in which the melody isplayed with the thumb and second and third finger leaving the other fingers of the right hand free to play interesting embellishments and other contrapuntal effects.

Another style of playing is one in which the right hand plays the 'melody part in the octave below middle C on the piano (in which range the piano notes are particularly rich in harmonic development) and in which the left hand alternately plays bass notes at the low end of the piano and then crosses the right hand to play accompaniment chords and other figures on the unaccented beats of the musical score.

Still another interesting style of playing is one in which the players left hand is used to play the melody in the octave of keys lying below middle C on the piano, leaving the right hand free to play interesting embellishments, flourishes; and other patterns in the treble register of the piano. This style of playing is particularly effective when playing with an orchestra in which the bass part is carried by other instruments.

in general, the number of orchestral and instrumental possibilities oifered by a monophonic instrument disclosed herein, playable by the piano keys, far surpasses that of a complete polyphonic instrument such as the pipe organ provided with a. piano stop, in which there are sustained tone sources corresponding to all the piano keys.

The key operated switching circuits shown in Fig. 3

are usable for the tuning of substantially any type of oscillator employing inductance or resistance tuning elements connected in series. However, if the oscillator is to be tuned by substituting series connected capacitors for the tuning elements such as L106, then the connections between the switch contacts must be in reverse order, that is, instead of having the contact arm 75 connected to the break contactof the next adjacent lower note, it must be connected to thebreak contact of the next adjacent higher note. When capacitors are used as tuning eleme its, the connections to the contacts engaged by the switch arm should also be reversed.

While I have shown and described a particular embodiment of my invention, it will be apparent to thoseskilled in the art that numerous modifications and variations may be made in the form and construction thereof, without departing from the more fundamental principles of the invention. I therefore desire, by the following claims, to include within the scope of my invention all such similar and modified forms of the apparatus disclosed, by which substantially the results of the invention may be obtained by substantially the same or equivalent means.

I claim:

1. In an electrical musical instrument having an output system, the combination of an oscillator having first and second terminals; a tuning circuit connected across said terminals and comprising a plurality of separate impedanceelements connected in series; a plurality of playing keys, each key having associated with it for operation thereby a switch arm cooperating with a makeswitch contact and a break-switch contact; means connecting the switch arm associated with the lowest key to the first terminal; means connecting the make-switch contacts respectively to the junctions between the series of separate impedance elements; means respectively connecting the switch arms operable by all but the lowest key to the break-switch contacts of the next lower key; a selector switch for each key; means connecting one contact of each selector switch to said first terminal; means connecting the other contacts of the selector switches respectively to the switch arms of their associated keys; and operating means common to all f the selector switches.

2. In an electrical musical instrument having an output system, the combination of an oscillator having first and second terminals; a tuning circuit connectable between said terminals and comprising a selectable number of electrically separate impedance elements connected in series; a keyboard comprising a plurality of playing keys; a plurality of normally closed switches operable by the keys respectively and connected in series to the first of said terminals; and switch and circuit means respecively operable by the keys to connect one of the junctions between the series of impedance elements to said first terminal through the normally closed switches and to open the normally closed switch associated with the operated key; whereby the lowest of a plurality of keys depressed at the same time will be effective to determine the number of impedance elements which are effectively connected between said terminals, and, due to the provision of separate tuning impedances, the oscillator will oscillate continuously even though one of the tuning impedance elements is shortcircuited temporarily upon operation of the switch means, a plurality of selector switches, one for each of said keys and each having one contact connected to said first terminal and having its other contact connected to the normally closed switch of its associated key, and common means for operating said selector switches, whereby when the selector switches are closed the highest of a plurality of keys depressed at the same time will be effective to determine the number of said inductance elements elfectively connected in the tuning circuit and thereby determine the frequency of oscillation of the oscillator.

3. In an electrical musical instrument having a keyboard comprising a plurality of keys and in which there is a two-position selector element which, when in its first position, causes the sounding of a tone of pitch corresponding to the highest of several depressed keys and which, when in its second position, causes the sounding of the lowest of several depressed keys, the combination of an output system having a terminal the potential of which determines the intensity of the tones produced, control switches respectively operable by the playing keys, a plurality of bus bars, means connecting one contact of the control switches of groups of adjacent playing keys respectively to said bus bars, means connecting the other contacts of the control switches to a point of constant potential of value such that when applied to said terminal of the output system will render the latter effective to produce a tone, range selector switches to connect the bus bars in series, and a switch operated by said selector element selectively to connect the bus bar vassociated with the highest group of keys to said terminal of the output system, or to connect the bus bar associated with the lowest group of keys to said terminal.

4. (In an electrical musical instrument having an output system, the combination of an oscillator including a tuning circuit comprising a plurality of series connected impedance elements, a plurality of playing keys, switches operated by the keys, circuits controlled by the switches.

and including some of said impedance elements to cause the oscillator to be tuned to the pitch of the highest of several keys of a group which are depressed at the same time, other circuits controlled by the switches and including some of said impedance elements to cause the oscillator to be tuned to the pitch of the lowest of several keys of a group which are depressed at the same time, and selectively operable means to render the circuits effective alternatively.

51 In an electrical musical instrument the combination of an oscillator having two terminals, a tuning circuit comprising a plurality of separate'tuning impedances in series between said terminals; a plurality of playing keys, each key having associated with it for operation thereby a switch arm cooperating with a make-switch contact and a break-switch contact; means connecting the make-switch contacts respectively to the junctions between the series of tuning impedances; conductors respectively connecting the switch arms with the break-switch contacts associated with their next adjacent lower keys, whereby the switch arms will be connected in series when none of the keys is operated; means connecting the switch arm at the end of the series to one of said terminals; a selector switch for each key; a conductor connecting one contact of each selector switch with one of said switch arms; means connecting the other contacts of the selector switches to the terminal to which the switch arm at the end of the series is connected; and manually actuatable means for operating the selector switches.

References Cited in the file of this patent UNITED STATES PATENTS 2,250,065 Koehl July 22, 1941 2,274,199 Hammond Feb. 24, 1942 2,276,390 Hanert Mar. 17, 1942 2,365,566 Langer Dec. 19, 1944 2,468,062 Hanert Apr. 26, l949 2,543,629 Hanert Feb. 27, 1951 

